President Obama called NBA player Jason Collins Monday to offer his support after Collins announced he's gay, becoming the first openly gay major league professional athlete, CBS News Chief White House Correspondent Major Garrett has learned. The president offered congratulations and support on Collins' courage and willingness to be the first in the four dominant pro sports to make this announcement. First lady Michelle Obama also showed her support for Collins on Twitter Monday. "So proud of you, Jason Collins! This is a huge step forward for our country. We've got your back!" she tweeted, signing it "-mo," which indicates...